When to Plant Corn in Keweenaw County, MI
Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.
Keweenaw County, Michigan is in USDA Zone 4a. The average last spring frost is May 19 and the first fall frost is October 1, giving you a growing season of approximately 135 days.
At an elevation of 1,035 feet, Keweenaw County receives approximately 40.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Corn to ensure they mature before fall.
Keweenaw County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.9
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Plant Water Budget
Corn Planting Timeline — Keweenaw County, MI
Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | June 2 | Jun 2 – Jun 23 |
| Harvest | August 4 | Aug 4 – Sep 29 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
60–100 days
Soil pH
6 – 7
USDA Zone
Zone 4a
Growing Season
135 days
Growing Tips for Keweenaw County
Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Corn in Other Locations
Frequently Asked Questions
When should I plant Corn in Keweenaw County, MI?
Keweenaw County is in Zone 4a with an average last frost of May 19. Plan your Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Keweenaw County, MI?
Keweenaw County, Michigan is in USDA Hardiness Zone 4a. The average last spring frost is May 19 and first fall frost is October 1.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Keweenaw County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.
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